1. Field of the Invention
Thee present invention relates to a waterproof door lock for an automotive vehicle, and more specifically to a waterproof structure of a door lock mechanism which can effectively protect the lock/unlock mechanism from water for prevention thereof from rust and freezing.
2. Description of the Prior Art
As is well known, a door lock for an automotive vehicle is assembled in an automotive vehicle door to lock/unlock the vehicle door. An example of the prior-art door locks is disclosed in Japanese Published Examined (Kokoku) Application No. 46-15882, for instance, which is hereby incorporated by reference.
Usually, the door lock mechanism is assembled on a base plate formed by a press machine, and a control mechanism for controllably actuating a latch locking/unlocking pawl is pivotally mounted on the surface of the base plate. This control mechanism is composed of a plurality of externally extending levers (i.e. an outside handle lever, an inside handle lever, a lock handle lever, etc.) and some other lock/unlock levers interconnecting these handle levers, which are all pivotally supported by many support pins fixed to the base plate. That is, a number of pivotal members extending outside are incorporated as control mechanism in the door lock.
On the other hand, since rain water or washing water flows into the door lock easily along the inside surface of the door or door window glass, there exists a problem that the mechanical elements arranged within the door lock are rusted by water and therefore will not operate reliably. In addition, in winter or in cold districts, since water flowing into the door lock is frozen, there exists another problem that the door lock will not be actuated and therefore door locking operation is disabled.
To overcome the above-mentioned problem, it may be considered to completely cover the whole control mechanism by a waterproof protective cover. In practice, however, since the control mechanism includes a plurality of levers (an outside handle lever, an inside handle lever, a lock knob lever, etc.) extending outside, there exists a problem that water easily enters the door lock mechanism through openings through which the levers are led out outside and therefore it is impossible to solve the above-mentioned drawbacks (rust or freezing) involved in the prior-art door lock for an automotive vehicle.